In vivo procedures for assessment of hair greasiness.

Synopsis Greasy hair is a common problem in Europe. The first step in developing anti-grease hair products must be to establish a sensitive protocol for measuring any changes in perceived hair greasiness. Sensitive clinical trials and in vivo evaluation methods of determining hair greasiness have been developed that show significant differences in the perceived hair greasiness following the use of different shampoos. Products tested in two clinical trials for efficacy as anti-grease shampoos were an anti-grease shampoo containing 2% 3,4-thiolanediol as the active ingredient, and a baby shampoo based on mild surfactants. The same placebo shampoo based on ether sulphates used in typical European shampoo formulations was used in both tests. A shampoo containing 2% zinc pyrithione was included in the trials as a control, since there were indications that this would increase the amount of hair greasiness. Neither of the test products were shown to be effective anti-grease shampoos. The shampoo containing 2% zinc pyrithione was shown to produce significantly more greasiness than both the placebo and the test shampoos. Since significant differences could be shown between the different shampoos, the protocol and in vivo evaluation techniques used in these clinical trials are considered to be validated.